The present invention relates to a case, and more specifically, to a boxboard-made case for use in packaging facial tissues or the like which is provided with an arrangement for forming an opening therein.
Conventional cases for packaging facial tissues, for example, are boxboard-made and have a rectangular box construction in which annular perforations are provided on a top wall of the box for forming an outlet opening through which tissues are to be drawn out one after another. Said opening is formed by removing a portion surrounded by the perforations by tearing it off along the perforations.
In such a case for facial tissues, a synthetic resin film is placed on the underside of the top wall and at a position corresponding to the opening, said film having a slit centrally formed therein which extends in the longitudinal direction of the opening so that when a tissue is drawn through the opening, it is subjected to some resistance, whereby one tissue only is allowed to be drawn out at one time, while a succeeding tissue is allowed to project partially from the opening.
However, the conventional cases have a drawback in that the perforations provided for forming an opening are merely such that small perforations are intermittently arranged on the top wall, so that the gap between each pair of adjacent perforations is as thick as the boxboard material. Hence when the portion surrounded by the perforations is torn off along the perforations in order to form the opening, there will occur some resistance at the gaps between the individual perforations.
Therefore, when breaking the perforations by pulling a cover plate portion, i.e., the portion surrounded by the perforations, in order to form the opening, it is difficult to guide the force of tearing from one perforation to another. Thus, the force of tearing may go astray from the direction of the perforations and no smooth tearing can be performed, causing, for example, the cover plate portion to be broken halfway so that tearing has to be done again with a remaining portion thereof, or the tearing to be directed outwardly of the opening so that the opening is formed in a very unsightly way.
It is a usual practice to perform tearing while applying a finger tip force along the perforations in order to facilitate smooth tearing. However, the trouble with this practice is that the cutting of the perforations under the thrust of a finger tip is not only time-consuming, but also it may result in cutting the film provided on the underside of the top wall or removing the bond between the underside of the top wall and the film, thereby adversely affecting the function of the film.